Heteroepitaxial growth of semiconductors usually suffers from strain relaxation dislocations formation due to the difference (mismatch) of lattice parameters. One solution proposed in the literature is the selective growth of semiconductor material in narrow oxide trenches. This technique, called Aspect Ratio Trapping (ART), allows for the trapping of defects at the bottom of the narrow oxide trenches using the sidewalls of the narrow oxide trenches. As a result, the top part of the semiconductor grown in the trench can be relaxed and without (or with reduced) defects. One example of such an ART technique is described in U.S. Patent Application Publication No. 2010/0216277.